Materials used in manufacturing processes may be associated with a specification that indicates particular characteristics that the materials are expected to possess. For example, the specification may indicate electrical properties of a particular material have to meet the specification. To determine whether the materials meet the specification, the materials may be tested. Tests to determine electrical characteristics of the materials may be destructive or non-destructive.
Generally, destructive tests include tests that extract a sample portion of the material to be tested. For example, a sample portion of the material may be cut off of a block of the material. The sample portion may then be subjected to tests to determine properties of the sample portion. However, when the material is inhomogeneous, the sample portion may not be representative of other portions of the material.
Non-destructive testing may include subjecting a sample portion or an entire body of the material to tests to determine properties of the material. However, non-destructive testing methods may also have difficulty identifying inhomogeneous properties of the material or properties that depend upon test conditions that are varied. For example, swept frequency radar (also referred to as inverse synthetic aperture radar (ISAR)) may use a variable frequency to determine a dielectric constant of a block of a material. However, ISAR may have difficulty determining frequency dependence of the dielectric constant since ISAR may sweep the frequency during testing.